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Tamochifen breast cancer can help to slow down the incurable hereditary muscle disease. Researchers at the University of Geneva report with their colleagues that the drug has prolonged the life of mice with diseases.
Miotubular Myopathy is a serious hereditary disease affecting one in 50,000 newborns. A genetic defect leads to muscle atrophy. In particular, due to the weakness of the respiratory muscles, this rare disease usually leads to death in the first two years of life.
Treatment still does not exist, but at least it could slow down the progression of the disease: researchers at the University of Geneva and Strasbourg reported promising results in experiments on animals with tamoxifen.
Tamocifen has been used for years in the treatment of breast cancer and has some interesting features in terms of muscle fiber protection, as announced by the University of Geneva. In a previous study, the researchers had already successfully tested the medication for their effect on a common muscle disease, Duchenne muscular dystrophy. This refers to one in 3,500 boys; life expectancy is 30 years. Clinical trials are underway now.
Based on these promising earlier results, scientists around Leonard Scapozza have now also tested the efficacy of tamofifen in myotype myotype muscle models. They report on the results in the journal Nature of Communication.
However, the two diseases cause muscle weakness in different ways: Myotubular myopathy lacks an enzyme called myotubularin. Without it, a protein called dinamine 2 is accumulated, making the muscles atrophy. Tamofifen starts with Dinamine 2.
Mice with the same symptoms as babies with myotubular myopathy survived twice as long, with the lowest dose tested, with a maximum dose of as many as seven times longer on average than untreated mice. The highest dose was – equivalent to the muscular body – used in breast cancer.
In addition, the drug slowed down the progressive muscle paralysis or even led to a deadlock. Muscle strength was also significantly increased by treatment.
Early access prevents paralysis
The researchers began treatment with tamoxifen when the first symptoms appeared in about three weeks of mice. A Canadian research group from Toronto started earlier, and mice did not develop signs of paralysis, the University of Geneva wrote.
In the meantime, there are also research efforts to treat severe hereditary disease through gene therapy. His efficiency and security, however, should last for years, the author of the study by Olivier Dorchies of the University of Geneva speculates.
Since tamofifen has already been approved for human use, and while clinical trials for muscular dystrophy have already been rising, researchers hope that treatment with tamoxifen will be much better in myotubic myopathy.